Exhibit No. 1: Pearl Harbor: Intercepted Messages Sent by the Japanese Government, by the Pearl Harbor Committee, 1945
While investigating the Pearl Harbor attack, the joint committee heard testimony concerning intercepted Japanese government messages, particularly a 14-point message transmitted on December 6 and 7, 1941. That message mentioned escalating tensions between Japan and the United States and set a time for the Japanese embassy to present an ultimatum to the U.S. government: 1:00 a.m. (7:00 a.m. Hawaiian time).
Records of Joint Committees of Congress, National Archives and Records Administration
The Pearl Harbor Attack
On December 7, 1941, Japan attacked the United States Pacific Fleet at Pearl Harbor, Hawaii, killing thousands and destroying U.S. military ships and planes. Congress declared war against Japan the following day. At the end of the war, after seven military and presidential investigations had identified different reasons for the lack of U.S. preparedness at Pearl Harbor, Congress created a joint committee to review possible lapses in intelligence. Its findings led Congress to pass the National Security Act of 1947 to modernize national security agencies and coordinate military readiness.
The completely ineffective liaison between the Army and the Navy in Hawaii at a time when the fullest exchange of information was absolutely imperative dictates that military and naval intelligence, particularly, must be consolidated.
Pearl Harbor Committee, Investigation of the Pearl Harbor Attack, July 20, 1946